Trolley duct



Oct. 20,1936. w. H. FRANK TROLLEY DUCT Original Filed April 30, 1934 2 Sheets-Sheet 1 W. H. FRANK TROLLEY DUCT Oct. 20, 1936.

Original Filed April 30, 1934 2 Sheets-Sheet 2 Ad I mvig'rolz. .BY J .flrww/ ORNEY.

, Patented Oct. 20, 1936 PATENT OFFICE mommy nnc'r H. Frank. Detroit, Mich, assignor to Bulldog Electric Products Company, Detroit, Mich, a corporation of West Virginia Original application April so, 1934, Serial No. 723,053. Divided and this application May 6,

1935, Serial No. 20,115

13 Claims. (01. 241 -3) This invention relates to trolley ducts for electrical distribution systems.

Trolley ducts are generally made of duct sections joined end to end by separate couplings,

5 and it'is, by now, common practice to have the bus bar couplings effected at the points of duct coupling.

It has been proposed (see Pat. #2,01-i,729, filed October 29, 1934) to provide in trolley duct runs, at points remote from section couplings, intermediate entrances whereby trolleys may be insorted into or removed from 'a duct run between ends thereof; and, it has further been proposed to provide movable covers to "close these entrances and to maintain without interruption the continuity of the rails of the duct along which ridetrolley rollers.

It is proposed by the present invention to provide novel duct constructions in the nature of a trolley entrance and drop out means having movable covers for maintaining without interruption the continuity of the duct rails; the movable covers, in addition, function to connect adjacent ends of duct sections and couple them physically and electrically, and also function to provide access to the interior of the duct at the section couplings whereby'manipulation of the bus bar splices may readily be effected.

Further objects and aims of the invention will presently understood upon reference .to the appended drawings, which show parts of an electrical distribution system, reference being had to the following detailed description, which aids in an understanding of these drawings. In these drawings,

. Fig. 1 is a top plan view of a trolley bus duct at a bus duct splice and trolley entrance, hinged covers thereof being shown in closed position;

Fig. 2 is a similar view but with the movable covers removed;

Fig. 3 is a side elevation as if in the direction of the arrow 3 of Fig. 1, with the hinged covers shown in closed position in full lines and in open position in dotted lines;

Figs. 4 and 5 are sections on lines 3-5, 5-5 of Fig. 1;

Fig, 6 shows a bus splice means.

It will be understood that a run of bus duct comprises bus duct sections, joined end to end to provide a bus duct run. Each section of bus duct comprises a section of duct of sheet metal havingsides II, a bottom l2, and a top It, the latter having a narrow central slot l5. Formed in the bottom and top walls of the duct are two sets of beads IE and IT. The set of heads is provide grooves for receiving bus bars I8 which are partially enclosed by insulation l9 rolled around the bus bars before the bus bars are assembled with respect to the duct, and the walls of these grooves firmly hold the bus bars and the 5 insulation in place without requiring any additional securing means.

One end of each bus duct section is cut away on its ,top surface and partially down its sides, as best indicated in Figs. 1 to 3, at lines C for 10 a considerable distance from the very end of the bus duct section. Firmly anchored and in the duct, between the sides thereof and the bus bars are rigid strips 22 preferably, but not necessarily, of insulation, and these have ends project- 15 ing beyond the end of the duct section a considerable distance. One end of each of these strips 22 is secured against sliding with respect to the bus duct by screws 23 which tap thei'einto through holes in the sides of the duct, the strips being anchored by these screws and also by their frictional engagement with the sides of the duct and the insulation I9 enshrouding the bus bars. The anchored strips 22 aid inaligning the duct sections. Secured by the screws 23 to the sides of the duct are mounting plates 24, and to these plates are pivotally connected, as by rivets 25,

' movable covers 26. Each of these covers is L shaped in cross section and substantially takes the place of the cutaway portions of the duct top wall. The covers 26 are separated by a slot 21 which aligns with the slot l5 to continue the latter and provide a passage through which may move the trolleys of the system. The covers 26 are further provided with sets of beads 28 and tionsand these have latching fingers 33 which project upwardly through holes 34 formed in ears 35 bent transversely from the ends of the covers 26. The latches serve to latch the covers in place,

when duct sections are joined, so that the covers may secure duct sections to one another and form a continuous enclosed duct. The engagement between the latch plates 32 and the covers 25 provides a grounding connection between adjacent 5 I ends of duct sections, and assures a continuous ground throughout the entire duct system.

Inasmuch as each bus duct section is preequipped with its bus bars and their insulation, it

is necessary to provide at each duct splice, a

readily manipulable bus bar splice of a character.

a continuous narrow riding slotwidened at a duct splice point, and a movable cover for narrowing that is suitable for bus duct use. Thebusyduct splice obviously'must be such that it,will notsuch a character that the splice means, compris- Y ing a C strap 42, may be mounted on the end of the bus bar at the end of a duct section to form a- .socket into which may be thrust the end of the bus bar at the end of another duct section so that adjacent bus duct sections may be joined to each other merely by bringing together ends of adjacent sections-in the proper manner and properly I connecting the parts, the bus bars automatically coupling by such end-to-end joining of the duct sections. 1

It is observed that the insulation strips 22 operate, not only to join sections of duct, but also to tighten up and wedge the bus splices and the bus bars, preventing loose connections and thus insuring good electrical contact between the bus bars and the splices and satisfactorily bracing the bus bars as contacts roll over their splices.

It will be observed that the bus duct of the sys tem' is so constructed that the bus duct splices provide trolley entrances and also access points for the bus bar splices, and this feature distinguishes the bus duct system of this application from bus duct systems heretofore known where trolley entrances are remote from couplings and where bus bar junctures are comparatively inaceessible because they are not located at proper points with respect to the duct splices and the trolley entrances. I

I claim:

1. A'se'ctional trolley duct construction having a bus splice at a duct splice point and having a continuous narrow riding slot widened at the duct splice point to expose the interior of the duct and to expose the bus splice, and a movable cover fornarrowing the widened part of the'slot, the cover comprising two separate pieces, each secured at its ends to adjacent duct sections to form the duct splice means at such point.

2. A sectional trolley duct construction having a bus splice at a duct splice point and having a continuous narrow riding slot widened at the duct splice point to expose the interiorof the duct and to expose the bus splice, and a movable cover for narrowing the widened part of the slot, thev cover comprising two separate pieces, each secured at its ends to arfiacent duct sections to form the duct splice means at such point, certain'of the securements between cover pieces and duct sections being in the nature of hinges permitting the cover pieces to be swung open with hinge movements on axes transverse to the run of the duct.

3. A sectional trolley duct construction having a continuous narrow riding slot widened at a duct splice point, and a movable cover for narrowing the widened part of the slot, the cover comprising two separate pieces, each secured to adjacent duct sections to form the duct splice means at such point.

4. Asectional trolley duct construction having a continuous narrow riding slot widened at a duct splice point, and a movable cover for narrowing the widened part of the slot, the cover comprising two separate pieces, each secured at its ends to adjacent duct sections to form the duct splice means at such point.

5. Asectionaltrolley duct construction having the widened'part of the slot, the cover comprising two separate pieces, each secured at its ends to adjacent duct sections to form the duct splice means at such point, certain of the securements between cover pieces and duct sections being in the nature of hinges permitting the cover pieces to be swung open with hinge movements on axes transverse to the run of the duct.

6. A sectional trolley duct construction having a continuous narrow riding slot widened at a duct splice point, and a movable cover for narrowing the widened part of the slot, the cover being secured at its ends to adjacent duct sections to 'form the duct splice means at such point, the

cover comprising two separate sections which are relatively opposed and separated by a slot merging with the duct slot.

- tures at such notces and exposed by such cover pieces when open, opening of the cover pieces exposing the bus junctures and also widening the slot of the duct at the duct junctures to provide intermediate'trolley entrances.

8. In sectional duct construction comprising duct sections joined end to end and having rail portions in abutting relation to form continuous rails, means for aligning the duct sections end to end comprising rigid bars within the duct anchored to and connecting the abutting ends.

9. In sectional ductconstruction comprising duct sections joined end toend and having rail portions in abuttirm relation to form continuous rails, means for aligning the duct sections end to I end comprising rigid bars within the duct anchored to and connecting the abutting ends and received in grooves thereof.

10'. A sectional slotted tube trolley bus duct slots widened and notched at their ends to fur-- nish access thereinto at such ends, and movable covers, each comprising two separate portions, covering the notches and maintaining closed the tube at such ends, and bus bar junctures at such notches and exposed by such covers when open, opening of the covers exposing the bus junctures and also widening the slot of the duct at the duct junctures to provide intermediate trolley entrances, the covers being secured to adjacent duct sections to form duct splices.

11. A sectional slotted tube trolley bus duct construction comprising duct sections having rail portions in abutting relation to form continuous rails, the duct sections having narrow riding slots widened and notched at their ends to furnish access thereinto at such ends, and movable covers, each comprising two separate portions, covering the notches and maintaining closed the tube, at such ends. and bus bar .iunctures at such notches and exposed by such covers when open,

opening of the covers exposing the bus junctures and also widening the slot of the duct at the duct junctures to provide intermediate trolley entrances; the covers being secured to adjacent duct sections to. form duct splices, the securement between the covers and duct sections including hinges permitting hinge movement of the covers.

12. A slotted tube trolley duct having the slotted wall thereof cut away to provide a trolley entrance, two separate L-shaped portions similar to the cutaway portions and insertable in the entrance to replace the cutaway portions and separated by a continuation of the slot when in place, the portions being individually and hingedly connected to the duct on axes transverse to the run of theduct.

13. A slotted tube trolley duct having the slotted wall thereof cut away to provide a trolley entrance, L-shaped portions similar to the cutaway portions and insertable in the entrance to replace the cutaway portions and separated by a continuation of the slot when in place, the portions being individually and hingedly connected to the duct on axes transverse to the run of the duct whereby they may be swung away from the duct, the'duct having rails for rollers of trolleys, which rails are cut away at the entrances, the L-shaped portions having rails insertable into the cutaway parts of the duct rails to continue 'the duct rails even at the entrances.

WIILIAM EFRANK. 

